The International Gemological Institute (IGI) and the Gemological Institute of America (GIA) labs have recently examined the largest lab-grown diamonds they have ever seen grown with the high-pressure, high-temperature (HPHT) and chemical vapor deposition (CVD) methods.
In January, the IGI announced it had seen a record-setting lab-grown blue crystal piece of rough (shown at top), which weighs 150.42 cts. and measures 28.55 mm x 28.25 mm x 22.53 mm. This is believed to be the largest lab-grown diamond ever produced.
It also saw a second gray crystal weighing 141.58 cts. that measures 28.9 mm x 28.5 mm x 20.75 mm.
“The acceleration of technology in the lab-grown diamond sector is significant,” said IGI senior director of education John Pollard in a statement. “In addition to record-setting weights, they’re type IIb crystals, a semiconducting category associated with diamond-based electronics.”
Both diamonds were grown in Ukraine with HPHT by Alkor-D, a subsidiary of Meylor Global. Meylor had set the prior record for the world’s largest lab-grown diamond, which weighed 115 carats.
At last year’s JCK Las Vegas show, Meylor Global CEO Yuliya Kusher told JCK her company was working on a 200 carat diamond.
“I don’t think CVD can do that,” she said. She added that while most Chinese producers use HPHT, “they are making a lot of melee, [not even] 1 ct.”
Meylor Global is the official distributor of diamonds created by New Diamond Technology, the grower based in Russia known for producing record-setting diamonds. It is owned by Ukrainian national Timur Mindich.
In addition, the GIA recently examined the largest known polished lab-grown diamond it has ever seen produced by CVD.
The 16.41 ct. princess-cut diamond was grown with the CVD method by Shanghai Zhengshi Technology Co., which has been working on CVD technology since 2002.
The diamond evidenced no post-growth treatment and was graded G color, VVS2 clarity, GIA said.
“The first CVD diamond I examined in 2003 was a 0.23 ct. pear shape, with clear brown color,” said Dr. Wuyi Wang, GIA vice president of research and development, in a statement. “This 16.41 ct. laboratory-grown diamond demonstrates the advances in CVD growth technology.”
Most U.S.-based companies, including WD Lab Grown and Diamond Foundry, as well as Indian companies, grow diamonds using the CVD method.
Top: The 150 ct. lab-grown diamond (photo courtesy of International Gemological Institute)
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